Footwear with sponge rubber sole indirectly connected to the upper



Nov. 13, 1951 2,574,582

H- W. ROLLMAN FOOTWEAR WITH SPONGE RUBBER SOLE INDIRECTLY CONNECTED TO UPPER Filed March 1947 IN V EN TOR.

Patented Nov. 13, 1951 FOOTWEAR WITH SPONGE RUBBER SOLE INDIRECTLY CONNECTED TO THE UPPER Heinz W. Rollman, Waynesville, N. 0., assignor to Ro-Search, lnc., Waynesville, N. 0., a corporation of North Carolina Application March 22, 1947, Serial No. 736,539

" Claims. (01. 36-14) The invention refers to footwear and the method of manufacture of footwear of the type having a sponge rubber sole formed by the'vulcanization of a sponge rubber mix. The bottom of said sole is usually covered by a treadsole of dense rubber which is connected to the sponge rubber sole by its vulcanization.

One object of the invention is to provide footwear which has the advantages of the pe of footwear mentioned above and has an improved flexibility.

Another object of the invention is the creation of footwear which can be manufactured faster and with less expensive equipment and therefore at lesser cost than footwear of comparable types. A part of the invention is the method of manufacturing such footwear. Other objects and features of the invention are described hereafter in connection with the drawing, of which Fig. 1 is a cross section of a shoe, showing the main parts thereof in the relation according to the invention,

Fig. 2 is a cross section of a shoe with the upper connected edgewise to an-intermediarymember,

Fig. 3 is a cross section of a shoe where the insole and an intermediary member are both connected to the upper,

Fig. 4 is a cross section of a shoe where the insole is extended to form an intermediary member, Fig. 5 shows a cross section of a shoe with an intermediary member located so that it cannot be seen on the outside of the shoe,

Fig. 6 is a cross section of a shoe where the upper covers the extended part of the insole which forms the intermediary member,

Fig. 7 is the cross section of a shoe where the intermediary member is formed by two parts stitched together, one of which is the insole,

Fig. 8 shows a cross section of a shoe with a similar arrangement, but here the insole is only indirectly connected to the upper,

Fig. 9 shows a cross section of a shoe where the insole is vulcanized to the sponge rubber sole and carries a part stitched to the upper,

Fig. 10 shows the cross section of a mold to be used to carry out the method of manufacture of footwear according to the invention.

The footwear according to the invention is composed of a sponge rubber sole, which may be covered on its bottom by a treadsole, of an intermediary member partly vulcanized integrally to said sponge rubber sole and partly connected to the upper by stitching or other means of fastening. It is known to connect by integral vulcanization the upper directly to the sponge rubber sole in such way, that the upper is in contact with the sponge rubber forming mixture already during the time said sponge texture is developed and set. The rubber enters then partly into the material of the upper and creates a strong bond.

According to the invention said strong bond of integral vulcanization is used to connect the sponge rubber sole to an intermediary member which in turn is connected to the upper by stitching or other fastening means. Footwear having such intermediary members has an improved flexibility compared to footwear where the upper is directly integrally vulcanized to the sponge rubber sole, but has not lost the advantages of the older type of footwear.

As the stitching or other fastening of the upper to the intermediary member is done according to the invention after the vulcanization of the sponge rubber sole, the footwear may have an upper of material which would be otherwise damaged if subjected to the vulcanization. The absence of the upper from the assembly subjected to the vulcanization allows to replace the last as means for closing the vulcanization mold by a plate, which is far less expensive and much easier to heat. I

As may be seen in Fig. 1, the footwear accord ing to the invention comprises a sponge rubber sole I, covered on its bottom by a dense rubber tread sole 2. Integraliy connected to said sponge rubber is the intermediary member 3, of which one edge 4 is turned outwards. This edge may be partly or. wholly embedded in the sponge rubber mass. If partly embedded the edge 4 will form the cover of the outer upper rim of the sole. The edge 5 is turned upwards and connected to the upper 6 by stitching or by any of the various other means of fastening one part of an upper to another part. The upper 6 may cover the edge 5 as shown in Fig. 1 and reach down close to the bend of the part 3 or it may be fastened edgewise. as shown in Fig. 2. The member 3 is then fully visible. To increase the strength of the connection between the upper and the intermediary members the invention may provide, as shown in Fig. 3, an insole I with an upturned edge 8, so that upper or vamp 6 may be fastened to said edge 8 as well as to the edge 5. Here part 3 is integrally vulcanized to the sponge rubber sole l. The insole 1 is held in its place by fastening of its'edge 8 to the part 3, and can be made of lighter material.

Fig. 4 shows an arrangement where the insole I forms the intermediary member and an essential part of the connection between sole and upper. here the edge I or said insole l is turned upwards. The insole is vulcanized integrally to the sponge rubber sole I. The upper i is fastened after the vulcanization by stitching to the insole l, which is maoe in this case from material at least as strong as the upper '6.

In some cases it may be desirable not to show in the footwear according to the invention that part of the shoe construction which forms the indirect connection between the main part of the upper and the sole. As shown in Figs. and 6 the intermediary part 3 or the upturned edge 8 of the insole 1 are then fastened to the inside of the upper 6. a

The indirect connection of upper and sole may also be realized according to the invention by composing the member, forming said indirect connection, of two or more pieces, one of which preferably forms the insole of the footwear as shown in Figs. 7, 8 and 9. Said insole may be vulcanized integrally to the sponge rubber sole I. The part 3 is fastened by stitching or other means of fastening to said insole 1 before vulcanization. Said part 3 is fastened after vulcanization to the upper 5. The insole I may be connected directly to the upper 6 as shown in Fig. 7 or may only be indirectly connected as shown in F s. 8 and 9.

The edge 8 may extend over the whole circumference of the sole or may have interruption for open toe or open heel shoes or may exist in form of local protrusions only if the upper consists of straps as it is known for beach sandals. In connection with this invention the term rubber is used to designate any material with qualities similar to rubber from the hevea plant, may it be from other plants or a synthetic plastic. The term sponge rubber designates said rubber material in a texture having a multitude of open or closed pores as it is obtained by vulcanization or setting of rubber mixtures or latex containing a dispersion of gas or gas forming ingredients.

' The mold for the manufacture of footwear according to the invention comprises, as shown in Fig. 10, a mold for the sole, which preferably encloses the bottom, the sides and the upper rim of the sole. Into said mold III the treadsole 2 and the sponge rubber forming mixture II and the lower part of the member I or the insole are placed. The mold is then closed by the plate I2. This assembly can easily be vulcanized in a platen press, as the heat transfer required for the vulcanization, is favored by the flat surfaces of the mold l0 and of the plate l2. This is an advantage which is only offered by the footwear construction and the method according to the invention. This method places the sponge rubber mix and the intermediary member into the mold, applies heat to said assembly until the rubber is cured, removes thereafter said assembly from the mold and fastens the upper onto the intermediary member which in itself forms a part of the upper of the'completed footwear.

What I claim is:

1. An article of footwear comprising an upper connected to a sponge rubber sole only by an intermediary member of fibrous material of which a portion is vulcanized in situ to said sponge rubber sole and of which another portion forms an extending lip fastened by thread material to the lower rim of said upper.

2. An article of footwear comprising an upper connected to a sponge rubber sole only by an intermediary member of fibrous material of which a portion is vulcanized in situ to said sponge rubber sole and of which another portion forms an upstanding lip fastened by thread to the lower outer rim of said upper.

3. An article of footwear comprising an upper connected to a sponge rubber sole only by an intermediary member formed by an insole of fibrous material of which the central portion is vulcanized in situ to said sponge rubber sole and of which the extending free outer edge is fastened by thread material to the lower rim of said upper.

4. An article of footwear comprising an upper connected to a sponge rubber sole only by an intermediary member formed by two parts stitched together, of which one part is vulcanized in situ .to said sponge rubber sole and the other part is fastened to the lower rim of said upper. 5. An article of footwear comprising an upper connected to a sponge rubber sole only by an intermediary member formed by two parts stitched together, of which one part is vulcanized in situ to said sponge rubber sole and the other part extending upwards is laced to the outer lower portion of said upper. HEINZ W. ROLLMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 529,881 Shippee Nov. 27, 1894 542,175 Sharpe July 2, 1895 558,279 Higgins Apr. 14, 1896 1,174,054 Butterfleld Mar. 7, 1916 1,215,450 White Feb. 13, 1917 1,330,552 Saunders Feb. 10, 1920 1,753,872 Steed Apr. 8, 1930 1,937,074 Vicente Nov. 28, 1933 2,083,376 Heilhecker June 8, 1937 2,129,106 Szerenyi et a1 Sept. 6, 1938 2,284,620 Jayne June 2, 1942 2,364,373 Kleven Dec. 5, .1944 2,437,030 Hoza Man-2, 1948 FOREIGN PATENTS Number Country Date 543,053 Great Britain Feb. 9, 1942 

